Revert 21936 (which solves leaks with threads and weak references)
because it can introduce new SEGVs, and I'd prefer to ship with
the same bugs as 5.8.2, rather than different bugs.
Same bugs feels like the lesser of two evils.

Integrate:
[ 22133]
Add VMS to the list of "don't fork" OSes
[In the most simple way possible. Fix this properly post 5.8.3
to use $Config{d_fork} or something more robust]
p4raw-link: @22133 on //depot/perl: a56b3a00287b552dbc3a1b6102629c6e0aedfc2d

Integrate:
[ 22079]
Jarkko didn't move the cd ..\pod correctly. Given that it's been
like this pre 5.8.1, I suspect that no-one has used it recently.
p4raw-link: @22079 on //depot/perl: 2b712af56b0b0dbe19e312dacbdd227fb3dad324

Integrate:
[ 22049]
Fix minor problems with the CPAN release
1: Make Storable.xs to work on 5.8.2 and later (already in the core)
2: Ship the linux hints file
3: Ship Test::More for the benefit of Perls pre 5.6.2
4: Correct Makefile.PL to install in core for 5.8.0 and later

Integrate:
[ 22034]
Fix bug #24383, where hashes with the :unique attribute weren't
getting made readonly on interpreter clone. Also, remove the
:unique attribute from the hashes in warnings.pm, since they may
later be modified by warnings::register. Finally, adds tests for
the :unique attribute.
p4raw-link: @22034 on //depot/perl: 53c33732a73c90e26f613c11afdc5110e6a919ff

Integrate:
[ 21931]
Solaris gconvert() doesn't like ndigits == 0. Currently we have no
Configure test for troublesome gconvert(), so for now simply avoid
the optimisation that calls gconvert() in this case.